Researchers who remain convinced that a retrovirus is linked to chronic fatigue syndrome say they have proof their findings are correct, dismissing a recent comprehensive study that found no evidence of the link. That paper, published last week in the Journal of Virology by a team led by University of Utah researcher Dr. Ila R. Singh, is just the latest in a long line of studies conducted by scientists who have looked for evidence of the retrovirus XMRV in the blood of chronic fatigue syndrome patients but failed to find any. The scientific community’s consensus is that the original findings, reported in the journal Science in 2009, likely were the result of lab contamination, not a real infection in people.

At first, it looked like a breakthrough in the fight against chronic fatigue syndrome. Researchers said they found a mouse retrovirus called XMRV in the 68% of blood samples collected from 101 patients with chronic fatigue syndrome , while only 4% of blood samples from 218 healthy controls had evidence of the same virus. The research team said it was strong evidence that XMRV had something to do with causing chronic fatigue syndrome (CFS). The report had added credibility because it was published in the prestigious journal Science.

This post has been corrected. See note at bottom for details. The news this week was not good for those banking on a link between the retrovirus XMRV and chronic fatigue syndrome. A much-awaited study — arguably the most comprehensive search for evidence of XMRV in the blood of chronic fatigue syndrome patients to date — was published Wednesday in the Journal of Virology. That study, which examined the blood of 100 patients and 200 healthy peers, found no evidence of the retrovirus in anybody’s blood.

Researchers who remain convinced that a retrovirus is linked to chronic fatigue syndrome say they have proof their findings are correct, dismissing a recent comprehensive study that found no evidence of the link. That paper, published last week in the Journal of Virology by a team led by University of Utah researcher Dr. Ila R. Singh, is just the latest in a long line of studies conducted by scientists who have looked for evidence of the retrovirus XMRV in the blood of chronic fatigue syndrome patients but failed to find any. The scientific community’s consensus is that the original findings, reported in the journal Science in 2009, likely were the result of lab contamination, not a real infection in people.

It's been a year since the journal Science published a paper linking a retrovirus called XMRV to chronic fatigue syndrome -- an illness nobody has been able to explain or treat very effectively, to the enormous frustration of people diagnosed with it. The paper was met with expressions of hope and joy from many in the chronic fatigue syndrome community, who saw it as potentially leading to diagnostic tests, treatments and even, maybe, a vaccine and...

Government scientists have found traces of a mouse-related virus in 86% of patients with chronic fatigue syndrome, a discovery that is likely to reignite the controversy surrounding the virus widely known as XMRV. Nevada scientists first reported the presence of the virus in chronic fatigue patients in 2009, but at least three subsequent studies failed to detect it. On Monday, however, researchers from three different government agencies said they had found the virus in stored and fresh blood samples.

A new study casts further doubt on the role of a retrovirus, XMRV, in human disease, adding weight to the possibility that earlier studies finding a link between the virus and cancer and chronic fatigue syndrome may have been wrong. In the study, researchers from the National Cancer Institute and Johns Hopkins Medicine report being unable to find any evidence of the retrovirus in nearly 800 prostate cancer samples. "It is possible that XMRV is not actually circulating in the human population," the team wrote in its paper published by the journal Cancer Research last week.

At first, it looked like a breakthrough in the fight against chronic fatigue syndrome. Researchers said they found a mouse retrovirus called XMRV in the 68% of blood samples collected from 101 patients with chronic fatigue syndrome , while only 4% of blood samples from 218 healthy controls had evidence of the same virus. The research team said it was strong evidence that XMRV had something to do with causing chronic fatigue syndrome (CFS). The report had added credibility because it was published in the prestigious journal Science.

A study conducted in Germany contradicts at least two earlier studies that found a link between prostate tumors and a virus seen in some tumors. Researchers led by Drs. Reinhard Kurth and Norbert Bannert of the Robert Koch Institute in Berlin studied 589 prostate-tumor samples collected in Germany. The team reported Thursday in the journal Retrovirology that they found no traces of the xenotropic murine leukemia virus-related virus, or XMRV, in any of the samples.

For more than 100 years, medical literature has contained reports of a debilitating illness that causes prolonged fatigue, memory loss, headaches, cognitive problems and issues with digestion and sleep. Teddy Roosevelt, John Muir and Thomas Eakins all suffered from what was then known as neurasthenia. At that time, the recommended treatment for women was bed rest; men were advised to head to the Wild West. But neither treatment could be counted on to cure the disease. Toward the end of the 20th century, doctors came up with the term chronic fatigue syndrome (or, in Europe, myalgic encephalomyelitis)

This post has been corrected. See note at bottom for details. The news this week was not good for those banking on a link between the retrovirus XMRV and chronic fatigue syndrome. A much-awaited study — arguably the most comprehensive search for evidence of XMRV in the blood of chronic fatigue syndrome patients to date — was published Wednesday in the Journal of Virology. That study, which examined the blood of 100 patients and 200 healthy peers, found no evidence of the retrovirus in anybody’s blood.

A new study casts further doubt on the role of a retrovirus, XMRV, in human disease, adding weight to the possibility that earlier studies finding a link between the virus and cancer and chronic fatigue syndrome may have been wrong. In the study, researchers from the National Cancer Institute and Johns Hopkins Medicine report being unable to find any evidence of the retrovirus in nearly 800 prostate cancer samples. "It is possible that XMRV is not actually circulating in the human population," the team wrote in its paper published by the journal Cancer Research last week.

It's been a year since the journal Science published a paper linking a retrovirus called XMRV to chronic fatigue syndrome -- an illness nobody has been able to explain or treat very effectively, to the enormous frustration of people diagnosed with it. The paper was met with expressions of hope and joy from many in the chronic fatigue syndrome community, who saw it as potentially leading to diagnostic tests, treatments and even, maybe, a vaccine and...

Government scientists have found traces of a mouse-related virus in 86% of patients with chronic fatigue syndrome, a discovery that is likely to reignite the controversy surrounding the virus widely known as XMRV. Nevada scientists first reported the presence of the virus in chronic fatigue patients in 2009, but at least three subsequent studies failed to detect it. On Monday, however, researchers from three different government agencies said they had found the virus in stored and fresh blood samples.

In what may prove to be the first major breakthrough in the fight against the mysterious and controversial disorder known as chronic fatigue syndrome, researchers reported today that they have found traces of a virus in the vast majority of patients with the disease, commonly known as CFS. The same virus has previously been identified in at least a quarter of prostate tumors, particularly those that are very aggressive, and has also been linked...